Telescopic rangefinding gunsight automatic elevation adjustment



April 14, 1970 ALLEN 3,506,330

TELESCOPIC RANGEFINDING GUNSIGHT AUTOMATIC ELEVATION ADJUSTMENT FiledJuly 18, 1967 2 sheets-sheet 'l 1% J h N a Q "1] I l 1 a 7 I 'I b I v 3%v H l 1 l o 6 & fimmm I g I H| 1: L 1| "1 INVENTORQ RALPH Ci 14LLENATTORNEYS R. e. ALLEN 3,506,330 TELESCOPIC RANGEFINDING GUNSIGHTAUTOMATIC ELEVATION ADJUSTMENT Filed July 18, 1967 2 Sheets-Sheet 2April 14, 1970 7 V I III):

INVENTOR. RALPH G I4LLEN ATTORNEYS United States Patent ABSTRACT OF THEDISCLOSURE A telescopic gunsight having rotatable means for changing itsmagnification and a reference reticle such that adjustment'ofmagnification so that the image of a target of known size bears a presetrelation to the reticle is indicative of the distance to the target, andmeans; actuated by. the rotatable means for simultaneously changing theelevation of the line of sight relative to the gun.

BACKGROUND OF THE INVENTION This invention relates to telescopicgunsights having means for changing the degree of magnification of thetarget operatively connected to means for determining the range: to thetarget and automatically setting the proper elevation into the line ofsight as a result of the change in magnification.

Guns, and particularly artillery pieces, have heretofore been providedwith range finders which would automatically elevate the line of sightin accordance with the distance to the target. Such' range finders,however, usually are complicated in' structure and employ spaced prismsestablishing two different points of view and-are impractical whenapplied to a rifle. It is also known to provide a 'rifie with atelescopic gunsight having a rotary member for adjusting the opticalelements to change the degree of magnification of the shooters view ofthe target. Telescopic gunsights have also been provided with means forchanging the elevation of the line of sight but which were separate fromand not operationally related to means for changing magnification. Insuch sights it was necessary to determine the range by other means, thenmanually elevate the line of sight. Devices for changing the degree ofmagnification are exemplified by the patent to Burris et al. 3,161,716.

SUMMARY OF THE INVENTION The present invention comprises a telescopicgunsight having a rotary member for adjusting the degree ofmagnification of the target image and a fixed reticle so designed that atarget of known height can be viewed and the image thereof adjusted asto size until it bears a predetermined relation to thereticle, at whichtime the amount of rotation imparted to the magnifying means isindicative of the range to the target. That rotary member is drivinglycoupled to elevating means for the line of sight whereby the line ofsight is automatically adjusted for the correct range without furtheraction on the part of the shooter. In one form of the invention, therotary member is coupled by bevel gears to a threaded abutment in asupporting housing to advance or retract the abutment and a spring holdsan optical tube, the axis of 3,505,330 Patented Apr. 14, 1970 whichconstitutes the line of sight, against that abutment and causes it tofollow the same as the gears are rotated. The tube referred to ispivotally mounted in the telescope and engages the abutment near one ofits ends so that vertical movement at that end will effect tilting ofthe line of sight. A second embodiment is similar to the first butemploys an' electric motor to impart rotation to the magnifying meansand to the threaded abutment,

simultaneously. A third embodiment employs a radial cam on the rotarymember, which cam directly abuts a fixed stop in the housing and aspring causes the axis of the rotary member to move toward or from theabutment, depending upon the angular position of the cam.

BRIEF DESCRII TION OF THE DRAWINGS DESCRIPTION OF THE PREFERREDEMBODIMENT Referring first to FIG. 1, numeral 2 indicates a generallytubular structure constituting an outer housing for the telescopicgunsight of the invention. It is. contemplated that the housing 2 befixedly secured" to a rifle or the like in any customary manner so as tobe held rigidly thereon: Within the tubulafhous'ing 2 is a further tube4 within which erecting lens means 6 are slidably mounted for? axialmovement therein. The tube 4, at its rearmost enl, is preferably formedwith a gen-' erally spherical portion 8 having a socket 10 into which aball or pivot member 12 extends. The member 12 is fixed to the housing2. Thus, the outer or right hand end of tube 4 can be moved in anylateral'direction within the housing 2, there being suiiicient clearancefor this purpose. The optical elements 6 are provided with laterallyextending pins 14 projecting through an elongated slot 16 in the tube 4.Those pins 14 also extend into helical slots 18 and 20 in a sleeve 22rotatably carried by the outer surface of the tube 4. At its rear endthe sleeve 22 is provided with a pin or screw 24 extending outwardlythrough a circumferential slot 26 in the housing 2 and which fixedlyjoins the sleeve 22 to an adjusting ring 28 rotatably carried by theouter surface of the housing 2. Suitable objective and eyepiece lenssystems (not shown) are provided as. is customary. It will be obviousthat rotation of the ring 28 will cause the erecting lenses 6 to movelongitudinally within the tube 4 and relative to each other and thelenses are so designed that such movement willchange the degree ofmagnification of a target viewed through the eyepiece 30. That is, theimage seen by the viewer can be made larger or smaller. The structurethus far described may be considered conventional and substantiallyfully disclosed in the patent previously referred to. To achieve theobjectives of the present invention the sleeve 22 is provided at itsforward end with a bevel gear 32 rigidly fixed thereon. The bevel gear32 meshes with a further bevel gear 34 fixed on a screw-threaded plug36, threadedly carried by a support member 38 threaded into couplingmember 40 constituting a part of the housing 2. As shown, a. removableprotective cap 42 engages the support 38. A. central screw 44 isthreaded through the plug 36 and is provided with a head 46 accessiblefor manual adjustment when the cap 42 is removed. The central screw 44abuts, at its lower end 48, with the outer surface of tube 4 to thuslimit upward movement of that end of the tube. A suitable leaf spring 50is mounted within the coupling member 40 and bears at its free endagainst the bottom surface of the tube 4 so as to constantly urge thesame into abutting engagement with the screw 44. It will be obvioustherefore that rotation of the sleeve 22 will cause the gears 32 and 34to rotate. Rotation of gear 34 will cause the plug '36 to move upwardlyor downwardly because of its threaded connection to the support 38. Thecentral screw 44 rotates and moves with the plug 36 and thus changes thevertical position of the abutment end 48 thereof whereupon the spring 50will cause the tube 4 to tilt upwardly or downwardly about its rearwardend defined by the spherical portion 8 and this tilting movement willadjust the vertical angle of the line of sight established by the axisof the optical elements 6. The slots 18 and 20 are so configured thatthey properly coordinate the change in magnification and the degree oftilt of the line of sight.

Referring now to FIG. 2, there is shown therein a reticle generallydesignated at 52 and preferably located at the focus of the eyepiece, asis conventional. The reticle 52 comprises a transparent member havinglines or cross-hairs delineated thereon, such as the cross-hairs 54. Inaddition, a pair of short cross-hairs or lines 56 are provided on thereticle a fixed vertical distance apart. The spacing between the lines56 is predesigned so that operation of the means for adjusting thedegree of magnification will magnify an image of the target such that atarget of known height (for example, one foot) will appear to exactlyoccupy the vertical space between the lines 56 and the amount ofrotation to achieve that image size is indicative of the range to thattarget.

In operation, the shooter may select portions of the target known to beabout one foot high and adjust the magnification of the describedtelescopic gunsight until the selected portion of the target extendsfrom one to the other of the lines 56 and the resulting rotation ofsleeve 22 and tilting of tube 4 will tilt the line of sight the correctamount for shooting at that target at that range.

In the modification illustrated in FIG. 3, it can be assumed that theinternal optical system and means for adjusting the same is identical tothat described with reference to FIG. 1. However, the gears 32 and 34are omitted and the threaded plug 36 extends upwardly and outwardly ofthe housing 2 and has a Worm gear 58 fixed to its upper end. Instead ofthe adjusting ring 28 of FIG. 1, the sleeve 22 is provided with a gear60 fixed thereto and housed within an auxiliary housing 62 comprising apart of a coupling member 64 and which gear is exposed through a slot 66in the auxiliary housing. A supporting bracket 68 is mounted on thehousing 2 and defines a supporting bearing 70 for a shaft 72. At itsrear end the shaft 72 is provided with a gear 74 fixed thereon andmeshing with the gear 60. A second gear 76 is fixed on the shaft 72 andmeshes with a worm drive 79 on the output shaft of an electric motor 80mounted on the housing 2 by means not shown. At its forward end theshaft 72 has fixed thereon a worm drive 82 meshing with the worm gear58.

The operation of the embodiment of FIG. 3 will be obvious to thoseskilled in the art and provides a motor drive for changing themagnification of the target and simultaneously changing the angle ofelevation of the line of sight. It is contemplated that suitablecontrols be provided within easy reach of the shooter so that he maycontrol operation of the motor to effect the required change ofmagnification of the target in the manner already described and therebyproperly adjust the line of sight to the correct range. Obviously, theembodiment of FIG. 3 will include a reticle such as that described withreference to FIG. 2.

In the embodiment shown in FIGS. 4 and 5, the main elements of thetelescope are identical to those shown and described in FIG. 1 and thusidentical parts bear the same reference numerals and will not be furtherdescribed herein. In the FIG. 4 embodiment, however, the gears 32 and 34are omitted and a radial cam 84 is fixedly secured to the outer surfaceof the sleeve 22 at its outer end. The leaf spring 50 bears against theforward end of tube 4 and urges the same upwardly to cause the surfaceof the cam 84 to engage a fixed but manually adjustable abutment definedby an abutment screw 86 threaded through a support member 88 which inturn is threadedly secured to the housing 2. As in the form of FIG. 1, aremovable protective cap 42 is provided. When the cap 42 is removed,manual adjustment of the abutment screw 86 may be made, which adjustmentis maintained by spring washer 87.

As will be obvious, rotation of the ring 28 to effect the desired changein degree of magnification of the target image will cause the sleeve 22and cam 84 to rotate. Since the outer surface of cam 84 varies in aradialfdirection, such rotation will permit the tube 4 to be tiltedupwardly or forced downwardly to thereby change the vertical angle ofthe line of sight established by optical elements 6. The manner in whichthe shooter manipulates the gunsight of this embodiment is exactly thesame as that already described with reference to FIG. 1.

For convenience of illustration the spring 50 is shown at the bottom ofthe gunsight whereas in practice it will preferably be positioned partway up one side of the housing 2 to serve the dual purpose of holdingtube 4 against the tilt adjustment screw and also against a conventionalwindage adjustment member (not shown).

While a limited number of specific embodiments of the invention areshown and described herein, it is to be noted that the same are merelyillustrative of the principles of the invention and that othermodifications may be resorted to within the scope of the appendedclaims.

I claim: l

1. In a telescopic gunsight having optical means for establishing a lineof sight and for magnifying a shooters view of a target and movableadjusting means for changing the degree of magnification, fixed reticlemeans in said line of sight for indicating the degree of magnificationof a target of known height whereby movement of said adjusting means toestablish a predetermined relation between the shooters view of a targetand said reticle means is indicative of the range to said target, andelevating means for; tilting said line of sight in said gunsight, saidgunsight comprising: a housing adapted to be fixed to a gun; a barreltiltably mounted in said housing; said optical means including at leastone optical element within and movable along said barrel; said adjustingmeans comprising a sleeve rotatable about said barrel and meansresponsive to rotation of said sleeve for moving said optical elementalong said barrel; said elevating means being drivinglyconnected to saidsleeve for tilting said barrel in said housing and thereby tilting saidline of sight in response to rotation of said sleeve to establish aproper sight elevation for shooting at said target.

2. A gunsight as defined in claim 1 wherein said elevating meanscomprises spring means in said housing urging said barrel to tilttherein; abutments threadedly supported in said housing and limiting thetilting of said barrel by said spring; and gear means interconnectingsaid sleeve and said abutment whereby rotation of said sleeve adjuststhe position of said abutment and thereby the degree of tilt of saidbarrel,

3. A gunsight as defined in claim 1 wherein said sleeve is journalled onsaid barrel and tiltable therewith; said elevating means comprisingspring means in said housing urging said barrel to tilt therein; aradial cam extending around the outer periphery of said sleeve; and anabutment in said housing engaging the periphery of said cam to limittilting of said barrel and sleeve whereby rotation of said sleeve andcam changes the angle of tilt of said barrel 40 A gunsight as defined inclaim 1 including electric motor means arranged to rotate said sleeve.

5, A gunsight as defined in claim 1 including calibrating means formanually changing the direction of said line of sight independently ofoperation of said elevating means,

References Cited UNITED STATES PATENTS DAVID SCHONBERG, Primary Examiner10 T. H KUSMER, Assistant Examiner US. Cl. X.R.

